Liquid dropper construction



April 23, 1957 R. J. OLSON ET AL LIQUID DROPPER CONSTRUCTION Filed March 15, 1956 w 4 M m Z) J n 1 so Zm J wiw FHA W xy/L.

LIQUID DRUPPER CGNSTRUCTION Application March 15, 1956, Serial No. 571,800

8 Ciaims. (Cl. 141-24) This invention relates to liquid droppers and more particularly to a dropper of improved construction suitable for use in dispensing medicaments, reagents and other liquids, drop by drop, or in other small measured amounts.

It has heretofore been common practice in liquid droppers to provide a resilient rubber-like bulb fitted upon the upper end of a glass dropper tube by means of which the liquid to be dispensed may be drawn into the lower end of the tube and thereafter dispensed by squeezing the bulb. Various schemes have been employed in such constructions for retaining the bulb upon the tube and for providing a hermetic seal therebetween, but none has heretofore been entirely satisfactory in all respects. It has been common practice, for example, to provide a bead on the upper end of the tube arranged to be received in a circular groove formed in the inner surface of the bulb to retain the bulb in place, but the provision of the bead and groove on the two parts has caused undesirable manufacturing costs when the droppers are manufactured in large numbers. In lieu of the bead and groove arrangement just mentioned, the upper end of the tube has sometimes been made cylindrical and the bulb has been retained in place thereon simply by sliding the tube well upwardly into the bulb, but in this case the bulb must have a substantially greater axial length than would otherwise be necessary since that portion of the length of the bulb containing the tube cannot be squeezed.

One of the principal objects of the present invention is to provide a liquid dropper comprising a tube having a bulb on an end thereof, wherein the bulb is retained upon the tube in a new and improved manner. In this regard, the bulb is resiliently fitted over the end of the tube and is provided with a resilient flange extending radially from the mouth of the bulb and in forceful contact with a ring-like rim on a disc carried by the tube below the bulb. This flange, when the dropper is assembled, is resiliently and radially compressed throughout its area between the tube and the rim so that the forces of radial compression therein serve materially to increase the tightness of the fit of the bulb about the tube and thus prevent inadvertent removal of the bulb from the tube. With this construction, as will be explained below, only a minimum portion of the tube need extend into the bulb. A further object of the invention is to provide in a liquid dropper of the above construction, means integrally formed on the ring-like rim for gripping the flange of the bulb in such a way as to retain the flange in its proper position on the disc and also to produce still greater radial compression in the flange, thereby assisting in retaining the bulb in its operative position on the dropper.

Another object of the present invention is to provide a liquid dropper, of the character just stated, wherein the dropper is of two-piece construction capable of easy and inexpensive manufacture and assembly. Still another object of the invention is to provide a liquid dropper of the character stated wherein the dropper provides a cap for a container for the liquid to be dispensed.

These and other objects and advantages of the present invention will be apparent from the following description of a preferred embodiment thereof, taken with the accompanying drawing wherein:

Fig. 1 is an elevational view of a dropper made in accordance with the invention, the dropper being shown in position upon the top of a fragmentary portion of a container or bottle for the liquid that is to be dispensed;

Fig. 2 is an exploded axial cross-sectional view of the upper portion of the dropper, showing the parts thereof in their disassembled state;

Fig. 3 is a view similar to Fig. 2 taken on an enlarged scale substantially along the line 33 in Fig. 1 but showing the parts of the dropper in their assembled state and showing a modified flange on the bulb; and

Fig. 4 is a top plan view of the dropper.

In the drawing the numeral 10 designates a bottle or other container upon which a dropper constructed in accordance with the present invention may be threaded in order to provide a cap for the bottle. As previously indicated, the bottle may contain the liquid to be dispensed by the dropper. The dropper itself comprises a longitudinally extending tube 11 having a passage 12 formed therein that extends the full length of the tube. This tube may be slightly tapered so that its lower end has a somewhat smaller diameter than its upper end, as suggested in Fig. l. Adjacent its upper end the tube has a radially extending disc 13 integrally formed thereon so that the upper extremity of the tube provides an upstanding substantially cylindrical boss 14 that extends upwardly from the upper surface of the disc 13, the upper edge of the boss being rounded, if desired, as shown in Figs. 2 and 3. The disc 13 is circular in its configuration and upon its periphery there is integrally formed a cylindrical body providing an upstanding peripheral rim 15 and a depending skirt 16. The upstanding rim 15 is located concentrically with respect to the boss 14- and a plurality of inwardly extending lugs 17 are formed upon the upper edge of the rim so as to provide an overhang with respect to the disc. In the preferred embodiment, the inner tips of the lugs 17 angle downwardly as best seen in Figs. 2 and 3. The inner surface of the skirt 16 is preferably provided with threads-18 which may be engaged with corresponding threads provided upon the neck of the bottle or container 10 so that rotation of the dropper about its axis will cause the disc 13 to be carried downwardly into sealing engagement with the upper lip of the mouth of the bottle.

A bulb 20 of rubber or other pliable and resilient material, having a radially extending flange 21 formed thereon about its mouth 22, is fitted upon the top of the dropper body in the manner shown in Fig. 3. The mouth 22 of the bulb, when the bulb is in its unstressed state, has an inner diameter somewhat less than the outer diameter of the boss 14, and the outer diameter of the flange 21, on the other hand, is preferably approximately the same or, if desired, slightly greater than the inner diameter of the upstanding rim 15 formed about the periphery of the disc 13. Similarly the thickness of the radially extending bulb flange should beap proximately equal to or, if desired, slightly greater than the distance between the disc 13 and the tips of the inwardly extending lugs 17. As best seen in Fig. 3, the bulb 20 is assembled or fitted upon the upper end of the dropper body by slipping the mouth 22 of the bulb downwardly over the boss 14 and simultaneously fitting the peripheral portions of the flange 21 on the bulb under the overhanging lugs 17 provided upon the upper edge of the rim 15, thereby bringing the lower surface of the flange 21 into intimate engagement with the upper side of the disc. During this assembly of the dropper,

. eral type.

3 it will 'be observed that the mouth 22 of the bulb is stretched as it is slipped downwardly over and about the boss 14 so that the peripheral edge of the flange 21 is caused to bear forcefully against the inner surface of the upstanding rim 15, thereby causing the flange to be compressed radially throughout its area, and vertically in the area under the downwardly angled tips of the lugs 17. These radial forces'of compression existing in the flange 21 cause the mouth 22 of the bulb to grip the outer cylindrical surface of the boss 14 more forcefully than would otherwise be the case, and they thereby cause the bulb to be securely retained upon the boss. The in-turned lugs 17 prevent the outer peripheral edge of the flange from being disengaged from the inner surface of the upstanding rim 15, and it will be noted that they also grip and compress the peripheral portions of the flange vertically. This vertical compression of the outer portion of the flange increases the state of radial compression existing in the flange, thereby increasing the force with which the mouth of the bulb encompasses the boss 14, and the grippingaction of the lugs 17 also positively retains the flange in contact with the rim 15. This gripping action of the lugs on the flange 21 may be increased by providing a raised rib 21a .on the upper side of the flange about its periphery, as shown in the bulb illustrated in Fig. 3. In spite of the relatively short length of the boss 14, the tight engagement of the mouth 22 of the bulbabout the boss, backed up by the radial forces of compression in the flange 21, forms a tight hermetic sealbetween the bulb and the boss, thereby permitting the dropper to be operated in the usual manner to draw liquid into the passage 12 at the lower end of the tube 11 and to cause the liquid to be expelled therefrom when the bulb is squeezed.

It will be observed from the drawing that the body of the present dropper, including the tube, the disc 13, and the upstanding rim 15 and skirt 16 are of a singlepiece construction that may be easily molded of any suitable material, such as any one of many available appropriate synthetic organic resins. The body of the dropper, for example, may be molded of polyethylene which gives to the tube 11 a slight flexibility that may be highly desirable in many instances and which .provides the disc 13 and the skirt .16 with a texture that will provide a tight sealing fit upon the mouth of the bottle 10 without the use of auxiliary washers or gaskets.

As a result of the characteristics of the present structure that cause the-mouth of the bulbto grip the boss 14 with more force than that whichwould be provided merely by the resilience of the mouth itself, the axial length of the boss may be reduced'to aminirnum and the thickness of'the-materialof the bulbmay also be less than that normally found in 'droppers of;this-.gen-

This substantially reduces the amount of material used in the manufacture 1 of each of :the

.droppers and, when the droppers are massaproduced, 'this' reduction in theamount of material employed. rep- Furthermore, it .will beobserved that because of thesshort length of theboss resents a substantial saving.

14, the bulb 20 may be squeezed along substantially its entire length. Because the boss extends-only a short distance into the bulb,.-the bulb may have a shorter axial length'than those found inthe prior art devices :beapparent to those skilled inthe art that variousother changes may be made in the construction of the dropper without vdepartingxfronnthe spirit and scppeof the appended claims.

We claim:

1. A liquid dropper comprising, a longitudinally extending tube open at its opposite ends, a radially extending disc located on said tube adjacent one of its ends so that the extremity of said end of said tube extends axially from one side of said disc to provide a relatively short substantially cylindrical protruding boss, an upstanding rim on said disc radially spaced from said boss and concentrically disposed thereabout, a bulb of resilient material having a mouth at one of its ends fitted over said boss, and a resilient flange on said end of said bulb extending radially from said'mouth and with the peripheral edge of said flange in contact with the inner surface of said rim, the inner circumference of said mouth being less than the outside circumference of said boss and the outside circumference of said flange being substantially as great as that of the inside of said rim when said bulb and said flange are in their unstressed conditions so that said mouth is resiliently stretched and said flange is resiliently and radially com- ;pressed throughout its area between said boss and said rim when said mouth is fitted over said boss, the forces of .-radial compression in said flange serving materially to increase the tightness of the fit of said mouth about said boss so as to prevent inadvertent removal of said ,bulb from said boss and to prevent leakage of fluid about-said boss.

2. A :two-piece liquid dropper comprising, a longitudinally extending tube open at its oppositeends, a radiallyextending disc integrally formed on said tube adjacentoneofdtsends so that the extremity of said end of saidtubeextends axially from one side of said disc to provide a relatively short substantially cylindrical protruding ,boss, an upstanding rim integrally formed on .said-oneside of said disc, said-rim being radially spaced from said-boss and being concentrically disposed there- .about a-bulb of resilient material having a mouth at one-of its ends fitted over said boss, and a resilient flange integrally formed on said end of said bulb extending radially from said mouth and with the peripheral edge ,of ,said flange ,in contact with the inner surface of ,said rim, the inner circumference of said mouth being less tha-ntheoutside circumference of said boss and the outside circumference of said flange being substantially ,as great as that of the inside of said rim when said bulb and .said.flange are in their unstressed conditions soflthat said mouth is resiliently stretchedand said; flange isresilien-tly and radially compressed throughout its area :betweensaidboss and said rinrwhen said mouth is fitted, over said boss, the forces of radialcompression in .saidflange-serving materiallyto increase the tightnessof the, fit .of said month about said-boss so as to prevent inadvertent removal of said bulb from said boss and to prevent leakageof fluid about said boss.

3. The combination set forth in claim 2, including aninturned edge on said rim over-lying the peripheral portion of .said resilient flange to prevent disengagement of the edge ofsaid flange from said rim.

4. ,The combination set forth in claim 2, including .a plurality of circumferentially spaced inturned lugs integrally formed on said rimand over-lying the peripheral portion of said resilient flange to prevent disengagement of the edge of said flange from said rim.

5. Thecombination set forth in claim 2, wherein said disc has a depending peripheral skirt thereon adapted to bereceived about the opening of a container for liquid that is to be dispensed by saiddropper, said dropper thereby providing a closure for said container. ,6. A liguid droppercomprising, a bottle caphaving reeess in itstop providing an upstanding peripheral rim aboutthe top of the cap a, longitudinally extending tube open at itsj opposite ends extending axially through said cap, the upperend of said tube protruding slightly above the bottom wall of .said recess so as to provide a short substantially cylindrical boss, a bulb of resilient material having a mouth at one of its ends fitted over said boss, and a resilient flange on said end of said bulb extending radially from said mouth and seated in said recess with the periphery of said flange in intimate contact with the inner surface of said rim, the inner circurnference of said mouth being less than the outside circumference of said boss and the outside circumference of said flange being substantially as great as that of the inside of said rim when said bulb and said flange are in their unstressed conditions so that said mouth is resiliently stretched and said flange is resiliently and radially compressed throughoutits area between said bos and said rim when said mouth is fitted over said boss, the forces of radial compression in said flange serving materially to increase the tightness of the fit of said month about said boss so as to prevent inadvertent removal of said bulb from said boss and to prevent leakage of fluid about said boss.

7. A liquid dropper comprising, a longitudinally extending tube open at its opposite ends, a radially extending disc integrally formed on said tube adjacent one of its ends, an upstanding rim on said disc radially spaced with respect to said tube and concentrically disposed with respect thereto, a pliable bulb member including a flange of resilient material overlaying said disc with the peripheral edge of said flange in forceful contact with the inner surface of said rim, the outer circumference of said flange being greater than that of the inside of said rim when said flange is in its unstressed condition so that said flange is radially compressed by said rim, and a plurality of circumferentially spaced inturned lugs integrally formed on said rim and overlaying and gripping the peripheral portion of said flange to prevent disengagement of said flange from said rim, said bulb member being adapted to be manipulated manually to draw liquid upwardly into said tube and to expel said liquid therefrom.

8. The combination set forth in claim 7, wherein said flange includes a raised rib integrally formed thereon about the periphery of said flange and underlying said lugs to improve the grip of said lugs on said flange.

No references cited. 

